The past is not dead. It has not even passed.

So wrote Spanish-born US philosopher George Santayana in The Life of Reason, his 1905-6 five-volume study of human progress. The phrase has since entered the language, even as its message has been stubbornly ignored by all, notably our leaders.

Today, for example, is the 27th anniversary of the USSR confirming the last of its troops had left Afghanistan after nine years of ruinous war. More than 14,000 Soviet troops lost their lives. Estimates vary, but it is thought up to one and a half MILLION Afghans, large numbers of them civilians, were killed. And to achieve what?

Afghanistan, a poor country when the conflict began in 1979, came out as the fourth poorest nation on Earth. After a further seven years of civil war the shattered nation finally fell to the Taliban, the political wing of the radical Islamist mujahideen fighters who Britain, the US and Saudi Arabia massively supported during the conflict.

The tale of this bloody exercise in futility was told to stunning effect by journalist and documentarian Adam Curtis in his 2014 film Bitter Lake (still available to watch at BBCi, and anyone with even a passing interest in this conflict should hasten there pronto).

Curtis placed the 1979-89 war in the context of Afghanistan’s long historic role in the struggle between empires of both West and East, doomed adventure after doomed adventure, savage moves in what became known as the ‘Great Game’.

Needless to say, the 2001 US-led invasion and subsequent conflict – its origins, conduct and likely outcomes – was woven into this same convoluted tapestry. Note that ‘likely’. Because at time of writing the outcome has seldom been in more doubt.

The Taliban now controls about 30 per cent of Afghanistan – including Sangin in Helmand Province, land hard won at the cost of 106 British soldiers’ lives – more than at any time since 2001.

Public confidence in the national unity government is waning because of the continued violence. The economy is in freefall. Government corruption is rampant. ISIS are wreaking murderous havoc.

And so here we go again. The US preparing to pour in hundreds of new combat troops. What price that the UK is next to re-deploy?